To me it seems that the D4 is the best bet. I haven't yet had a single spec of debris on my mirror and I have been using it since it was released. It also nails the focus left right and centre.

Luckily my D800 is dust and oil free too. However, my it has the left focus issue. Not too bad but it is something that bugs the hell out of me. I may send it in for calibration before the warranty runs out. Although I am strictly a centre focus point user. Old school film days habit. Works for me. That said I would expect a top tier Nikon to be flawless. Hence my griping about the left AF deficiency.